Sand blast barrel



Oct. 25, 1932. F. J. HULL SAND BLAST BARREL Filed March 5, 1950 4 Sheets-Sheet 1 Oct. 25, 1932. HULL 1,883,918

SAND BLAST BARREL Filed March 5, 1930 4 Sheets-Sheet 2 Filed March 5, 1930 4 Sheets-Sheet 3 abtoumq Oct. 25, 1932.

F. J. HULL 1,883,918

SAND BLAST BARREL Filed March 5, 1930 4 Sheets-Sheet 4 Patented Oct. 25, 1932 um ED STA res PATENT OFFICE FOSTER J. HULL, HAGERSTOWN, BEARYLAND, ASSIGNOR TO' PANGBORN CORPORATION,

OF HAGERSTOWN, MARYLAND, A CORPORATION OF IIIARYLAND SAND BLAST BARREL Application filed March 5, 1930. Serial No. 433,221.

The invention relates to a sand-.blast barrel: which has been developed primarily for the purpose; of cleaning elongated pieces of small lateral dimension, particularly fine twist drills suchas are used-by dentists. This apparatus is, however,,adapted to clean a large variety of small pieces for numerous purposes.

An important difliculty which has been encountered inv cleaning small pieces such as small diameter drills by treatment in a sand blast barrel has resulted fromthe necessity for allowing the abrasive to escape from the'barrel; This is accomplished by perforatingthe vbarrel-or drum. Such abarrel-has of necessity to be of comparatively heavy metalto Withstand-the wear incident to sand blasting and the perforations, if made large enough to be conveniently punchedorbored inthe heavy material also permit theiwork to fall out of the drum andv mix with'the used abrasive.

In order to meet the requirements (for such small drills, the perforations must not be largerthan-two one-hundredths of an inch in diameter. These holes must be quite numerous to provide for the discharge of the abrasive and if'they are to be formed by punching the material composing this portion'of the barrel wall, would have to be nomore than two one-hundredths of an inch in thickness orless for it is not practical to make holes in metal by punching, where the thickness of the material is greater than the diameter of the punch. I

VVhil'e it is possible to form the perforated portion of the barrel of cast iron and drill the-holesor perforations, this method is prohibitive on account of expense incident to drilling: the numerous fine perforations required, and barrels constructed in this way for the purpose in handare not so successful as the improved construction, which; is the subject of. the invention To: comply with the necessity for so constructing the barrel that it will retain the drills ,or tools and other small articles being cleaned or blasted, and at the same time to permlt the egress of the used abrasive and-to provide walls of suflicient thickness to give 1 a practical wearing factor, the lower or other perforated portion of the barrel, shown as mounted with its axis inclined and having its lower end portion perforated, has been constructed as to the perforated portion of metal strips bolted together by studs extending-in the direction of the length of the barrel. axis and spaced apart so as to release the abrasive and at the same time to retain the articles being treated.

In accordance with the preferred form of the invention, the open or perforated por tion of the barrel is made of straight strips heldtogether overlapped at their ends forming corners, so that the perforated portion; of the barrel is hexagonal or in any preferred polygonal form. It is, of course, not essential that the strips be straight but making them in this form cheapens the construction. In accordance with a later deVel- P through the sandblast barrel casing and driving mechanism at right angles to theeg worm axis, the sand hose and the hopper for introducing the work being shown in elevation.

Figure 2 is an elevation, of the entire machine ona reduced scale, the direction from perforated portion of the barrel as shown in Figure 1 on an enlarged scale.

Figure 8 is a fragmentary plan ofthe same.

Referring to the drawings by numerals,

each of which is used to indicate the same or similar parts in the different figures, the construction shown comprises a base 1, adapted,

to be secured to a suitable bench or table 2, or to be otherwise supported; this base 1 carriesat its upper end the main bearing member 3, which, in the form of the machine shown, comprises a hollow ring encircling the neck 5 of the sand blast barrel member 6. This neck 5 is a hollow cylindrical exteni sion of the barrel aligned with the barrel axis.

'Theselsurfaces may be lubricated from the chamber 11 by way of suitable openings16 leading from said chamber 11 to a groove 17 ;The main bearing member 3 is in the preferred form shown formed in two halves, 7

and 8, connected together by flanges 9 and bolts 10, the lower half 7 of the ring being in accordance with the details of the construction shown integral with the base memberl. This main bearing member 3 is hollow in the sense that it contains "and encloses an annular chamber 11 which is continuous as to thetwo parts 7 and 8 forming a single chamber which is intended to be packed with grease. The

grease is introduced in any suitable manner as by way of an opening 12 closed by a suitable screw plug. The sand blast barrel neck 5 which is encircled by the ring 3 is formed 'with an external cylindrical bearingsurface 14 and the ring'is formed with :1. corresponding internalcylindrical bearing surface 15.

in the outer bearing surface 15. The barrel 6 may be rotated in the bearings thus provided in any suitable manner as bymeans of a worm gear comprising worm l9 and wheel '20. The worm wheel or worm gear is 'shown in the form of a ring encircling the sand blast barrel neck 5 and secured thereto in anysuitable manner to rotate therewith as bymeans of the key 21, see particularly Figure 4. The'worm 19 on the other hand is mounted in suitable bearings in the lower half 7 o the main bearing 3.

From examination of the drawings, particularly Figure 1, it will be apparent that the teeth 24 of the worm gear or'ring gear 20 project into the grease chamber 11 and that the worm 19 is located in this chamber,

the bearings 2526 in which it is mounted being seated in the casting comprising the base 1 and the lower half 7 of the main bearing ring, and located at each side of the grease chamber 11 near each end of the worm 19. There is also a thrust bearing 27 at the end of the worm shaft 28 which is forward, for taking up the tangential stress incident to the driving of the worm wheel and the sand blast barrel. This bearing 27 may beheld in position in the castingl, 7, by a suitable cap 29. The worm '19 and wormshaft 28 may be driven in any suitable manner. In the form of the invention shown the worm is driven by a pulley 30, secured to a shaft 31 which is aligned with the shaft 28 and connected thereto in any suitable manner as by means of a thrust coupling 32. The shaft 31 is shown as mounted in a bearing 33 in a bracket34 connected to the casting, comprising thebase 1 and the lower half 7 of the mainbearing 3. This bracket 34 also carpulleys which, in addition to the driving pulley, 30,*include an idler 36.

v In the preferred form of the invention illustrated, the barrel axis is inclined with the vertical at a convenient angle shown as about '45 degrees. This arrangement is preferred though not essential to its useful operation,

The barrel neck 5, in the form of the invention shown, is supported within the bearing ring 7 8, by means of a removable flange 38 which takes overthe end of the bearing and is secured to the end of theneck in any suitable [manner as by means of cap screws 39. i

V Below and beyond the neck the cross-section of the barrel taken at right angles tothe 'barrelaxis is enlarged to give sufficient capacity. for the blasting operation, thus forming a shoulder 40 and the enlarged cross section thus formed is increased at the lower end of the'barrel. V

In the form of the invention shown the lower portion of the walls 41 of thebarrel consists of a perforated portion 42 which in theform illustrated in Figure 1, is built up of a series of thin strips illustrated in detail in Figures7 and 8,, the strips being indicated by reference character 43. As shown, they are, about. nineteen one-thoustandths or twenty one-thousandths of an inch in thickness and bored at their ends forming stud holes 44.

. These strips are connected together at their ends by studs 45, passing through the holes 44.;

to form ahexagonal perforated portion 46. The studs 45 which connect thestrips 43 at their 'ends to form the corners of the hex are parallel to the axis of the barrel and seated in tapped thIGHdQdllOlGS 47 formed for this a purpose in the thickened lower edge of the cylindricaliwallportion 41 of the barrel. It

- will be apparent from the description that the.

strips v43, laid one on top of the other at their ends which overlap at the corners,'are spaced -ries abearing 35 for the shaft 31 outside of the V thousandths of an inch or thereabouts forming slots 49 alternating with the strips and of a width equal to the thickness of the strips, the thickness of the strips used and/or the width of the .slots being varied according to the size of the articles being treated. To further support the strips one upon the other, they are shown as cupped or otherwise deflected by means of a round tool forming raised portions 48 of a height corresponding to the thickness of the strips. The cups or protuberances on each strip bear on the strip above or below to maintain the desired rigidity of the structure and the spacing of the strips. This serves to prevent deflection of the strips in either direction whereby part of the spaces might be enlarged permitting the articles being treated to escape with the abrasive. This is also a thicker base ring.

This method of construction provides at the minimum of expense a barrel wall of su'fficient thickness to have the necessary wearing factor and at the same time dispenses with the necessity for punching or drilling the perforations. The slots thus formed be tween the strips provide a convenient manner of escape for the used abrasive, the openings being of insufficient width to pass the work with the abrasive.

Figure 6 is a fragmentary view of the barrel showing the perforated portion in an alternative form. The perforated portion of the barrel in this instance indicated by reference character 142, consists of a series of rings 143 of equal diameter, laid one upon the other with their axes in alignment and in registration, the rings being secured together and to the lower edge of the cylindrical barrel portion 41 by means of studs 145 seated in lugs 146 formed on the lower edge of the cylindrical barrel wall. The rings are in the form of the invention shown formed with slightly raised bosses 147, which are bored at their centers to pass the studs 145. The rings are held tightly pressed together by the bolts, and the slight elevation of the bosses serving to space the rings pro-- vides arcuate slots 148 of corresponding width which in the preferred form illustrated is about nineteen one-thousandths or twenty one-thousandths of an inch, the width of the slots being made to correspond with the size of the work being treated. In the form of the invention shown the rings are provided with outward radially projecting flanges 149 of a thickness somewhat less than the inner peripheral portion of the rings whereby the width of the outer portions of the slots 148 is increased and consequently the Width and strength of the rings is increased without increasing the depth in a radial direction, i. e., of the slots 148. This increases the freedom with which the abrasive escapes rings and as they hear one upon the other,

they close the outer portions of the slots for short intervals surrounding each of the studs 145, which studs are spaced any convenient distance, six of the studs spaced at arcs of 60 degrees, being a convenient arrangement. i

The upper ring 150 is shown of a greater depth than the remaining rings forming the perforated portion. This ring takes a bearing in a corresponding circular rabbet 151, formed in the lower inner edge of the cylindrical portion 41 of the barrel. The upper portion of the inner surface of this ring is of frustro conical arrangement at 152 correspondingly reducing the inside diameter of the lower perforated portion of the barrel. 5

The base ring 153 is also of increased thickness and it provides a seat for the cover 154,

the exact arrangement of which is not material to the present invention, a suitable cover being described in connection with Figure 1.

In the form of the invention Fig. 1 the lower end or bottom of the barrel is closed by means of a cover or door 50, having a handle or grip 51 and held in position by latches or clips 52. The lower portion of the barrel below the neck is enclosed in a suitable casing or housing 54, shown as supported on and secured at its upper edge to the base 1 and the upper main bearing member 8 in any suitable manner as by means of cap screws 55.

This casing is provided with flex1ble packmg or flaps 56 enclrclmg and bearlng on the barrel to complete the closure and prevent a the escape of grit and dust around the barrel. The casing 54 is further provided with a door or cover 58 hinged at 59 on the casing to swing upwardly to theposition shown in dotted lines, and with a second door 60 hinged at 61 to swing from the full line posi- L tion to the dotted line position, the two doors closing a single continuous opening in the adjacent sides of the casing and being connected by a suitable fastener as a bolt or latch 62. This single combined opening provides for access to the barrel permitting the door or cover 50 in the bottom of the barrel ing is concentric with the axis of the barrel and aligned therewith. This tubular feed member 65 is supported in and by a suitable bracket 67 secured to the lower half 7 of the main bearing ring 3, which bracket is provided with an invertedU shaped cap 68 held in position in any suitable manner as by mean of bolts 69 whereby the tubular member is held in position preferably in alignment with the axis of the barrel or nearly, in which position it extends through the opening 66 in the barrel neck, the tubular member being stationary, while-the barrel rotates relatively to it.

The disclosure also includes a sand blast nozzle 68 shown in Figure 5, the rear portion 69 of this nozzle is held in a supporting collar or clamp 70 mounted on the lower end of the tubular feed member 65 and substantially parallel to the barrel axis, the discharge end 71 of the nozzle being directed obliquely toward the lowerpart of the barrel at the side and particularly at the inner'surface of .the rings 42. The nozzle is connected at its Y upper-end to a sand line 7 1 shown in the form of a flexible hose and to an air line 75, see F igure3, a portion of which is also preferably flexible, the sand line 74 is in turn connected to a nozzle sand pipe 76, and

the air line is connected to a nozzle air pipe 77. These pipes 76 and 77 are shown as straight, parallel to the barrel axis and con- 1 nected tothe upper end of the nozzle shank 69, being located in the opening 66 in the barrel neck at the side ofthe tubular member 65, which may be to advantage semicircular in cross section or substantially so to provide for the admission of these pipes. The

pipes 76 and 77 enter the barrel neck through slot 103 in the bracket 67 in Figure 3.

The construction also includes a hoppe 89 at the upper end of the tubular member 65. This hopper 89 has an oblique tubular extension 90 at its lower end, which tubular extension is in I the form of the invention shown teleseoped into the upper end of the tubular member 65 supporting the hopper in operative position as shown in Figure 1.

It will be apparent that the nozzle 68 can be rotated in the support or clamp 70 changing. the angle and the point of impact of the abrasive stream, that it may further be moved back and forth in said clamp in the direction of the length of the angular portion 69,and the axis of the sand blast barrel, the pipes 76 and 77 being at this time moved back and forth in the slot 103 in the bracket 1 67 which slot being wider than the outside diameter of the pipes 76 and 77, permits not only the sliding of these pipes but a limited 1; swing of one about the other with a correspondingly limited swing or angular motion of the nozzle as previously discussed.

. The nozzle 68 is shown in section in Figure The delivery end 102 is shown as threaded into the nozzle structure 68 which has a lateral sand or abrasive passage or. chamber 101 connected to the pipe 76 by passage 76 and an air nozzle directed across the chamber or passage 101. The air nozzle is connected to air pipe 77 by-passage'77;

1,sss,9 1,8

In the operation of the machine, the work being introduced into the barrel by. Way of the hopper: 89 "and the passage 65, and the abrasive being introduced into thehopper 99 in a convenient manner as by way ot'the doors 58 and 60, the valve 104 inthe compressed air pipe is opened causing a jet of com- 7 pressed air to issue from the air nozzle 100 and hence from the mixer nozzle 68. escape of compressed air through the nozzle into-the barrel by'way of the. discharge 102, sets up a sufiicientexcess pressure in the casing 54 and the hopper 99 and sufiicient vacuum in the hose 7 1 and the pipe 76 to start the flow of abrasive from the hopper 99 through hose 74 and pipe 7 6to the nozzle. The abrasive is thereby mixed in the nozzle 78 and ejected into contact with the work which is agitated by the rotation of the barrelpresenting its various surfaces to'the blast; The abrasive 1S dlscharged from the barrel into casing 54 through slots 01' perforations 43, the extremely slight width of the slots prevents the escape of the work which is usu ally in the form of twist drills or other elongatedarticles of small'diameter, butthe work may comprise any small articles. The escape of air and abrasive through theopening 66 around the tubular member 65 and the pipes 76, 7 7is preventedby flexible wipersi'nithe form of leather or rubber flaps or the like, 105, secured to the top inner'sujrface of the The barrel shoulder 40 below the neck, and bear- 7 ing at their edges against the tubular member 65"and said pipes 76, 77.

When treatment of the work has been completed, the doors 58, 60 are opened admitting the hands of the operator to the inside of the casing. Then the door 50 in the bottom of the'barrel is likewise opened, a suitable receptacle being preferably held in position beneath the barrel tocatch theworkwhich is thus released, or it may be-dropped on the door 60-shown in Figure 1 as horizontal in open position. y I For the purpose of stirring. or agitating the work to present 'difi'erent surfaces successivelyto the sand'blast, the barrel is rotated by means of the worm 19'engagingthe worm wheel 20 secured to the barrel neck 5. The neck 5 rotates int-he main bearing 3, thebearing surface of the worm wheel andthe bearing member being lubricated by grease with which the annular chamber 11 of the ring is packed, the grease escaping from this chamber 11 by way of passage 16 to the groove 17 whereby it is distributed on and between the surfaces 14 and 15 of the bearing and neck.

I have thus described specifically and in detail a sand blast barrel of small dimensions for treating small articles, particularly those of small lateral dimension, the description being specific and in detail in order that applicants preferred commercial structure herein illustrated as a basis for the specification and claims may be clearly understood, however, the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. A sand blast barrel having an enlarged cylindrical portion to contain the articles being treated, a reduced neck portion having a passage therethrough, said neck portion projecting upwardly from the barrel, a tube for the admission of work extending through said neck portion and a hopper connected to said tube, a nozzle projecting inwardly from said neck portion and pipes leading through said neck portion to said nozzle, and means for rotating the barrel, a stationary elongated bearing for the neck portion, the said bearing serving as the sole support for the barrel, the axis of the barrel and neck being inclined downwardly and the barrel portion being below the neck.

2. A sand blast barrel having a work chamber portion to contain the articles being treated, a reduced neck portion having a passage therethrough, said neck portion projecting upwardly from the work chamber, a tube for the admission of work extending through said neck portion and a hopper connected to said tube, a nozzle projecting inwardly from said neck portion and pipes leading through said neck portion to said nozzle, and means for rotating the barrel, said means comprising a ring gear mounted on the neck portion and a driving gear engaging the same, a bearing ring encircling said neck portion and supporting the barrel, said hearing member being slotted and having an annular grease chamber enclosing the slot from without, a ring gear projecting through said slot in the said grease chamber and said driving gear being enclosed in the said chamber.

3. A sand blast barrel having a neck portion concentric with the axis, a bearing member encircling the neck and supporting the barrel in upright position, a worm wheel in the form of a ring secured to and encircling the neck portion and a worm gear for driving the same, the bearing member being slotted and having an annular grease chamber enclosing the slot, the worm wheel projecting through said slot into the grease chamber, the worm being located in said grease chamber.

4. A sand blast barrel having a neck portion concentric with the axis, a bearing member encircling the neck and supporting the barrel in upright position, a worm wheel in the form of a ring secured to and encircling the neck portion and a worm gear for driving the same, the bearing member being slotted and having an annular grease chamber enclosing the slot, the worm wheel projecting through said slot into the grease chamber, the worm being located in said grease chamber, a hopper for the work having a tube projecting downwardly through said neck and means for supporting said hopper and tube, a nozzle in the barrel and air and abrasive pipes also extending through said neck to feed said nozzle.

5. A sand blast barrel having a neck portion concentric with the axis, a bearing member encircling the neck and supporting the barrel in upright position, a'worm wheel and a worm gear for driving the same, the bearing member being slotted and having an annular grease chamber enclosing the slot, the worm wheel projecting through said slot into the grease chamber, the'worm being located in said grease chamber, a hopper for the work having a tube projecting downwardly through said neck and means for supporting said hopper and tube independently of the neck, a nozzle in the barrel and air and abrasive pipes also extending through said neck to feed said nozzle, and means for supporting said nozzle on said tubular member, providing for rotative and longitudinal adjustment.

6. A sand blast barrel for treating small articles, the barrel having a portion formed of narrow fiat strips overlapping at their ends and secured at the overlapping portions to the remainder of the barrel, substantially half the strips thus overlapped at any point extending oppositely to the other half so that the ends of one half of said strips serve to space the ends of the other half of said strips, and vice versa, forming slots alternating with the strips of a width equal to the thickness of the strips, whereby the used abrasive is released and the work is retained.

7. A sand blast barrel for treating small articles, the barrel having a portion formed of narrow fiat strips overlapping at their ends and secured at the overlapping portions to the remainder of the barrel forming slots alternating with the strips whereby the used abrasive is released and the work is retained, some of the strips having protuberances which bear on the next adjacent strip maintaining the spacing.

8. A sand blast barrel for treating small articles, the barrel having a portion formed of narrow flat strips overlapping at their ends and secured at the overlapping portion to the remainder of the barrel, substantially half the strips thus overlapped at any point extending oppositely to' the other half so that the ends of one half of said strips serve to space the ends of the other half of said strips, and vice versa, forming slots alternating with the strips whereby the used abrasive is re'-' leased and the Work is retained, thestrips and the slots respectively being approximately two one-hundredths of an inch in width.

Signed by me at Hagerstown, Maryland, this 28th day of February, 1930.

r FOSTER J. HULL. 

